Where does “is” come from?

is (Bavarian) comes from Middle High German ist, from Old High German ist, from Proto-West Germanic *ist, from Proto-Germanic isti, from Proto-Indo-European h₁ēs- — to be.

Ancestry of “is”, step by step

StepLanguageWordMeaning
1Middle High Germanist—
2Old High Germanist—
3Proto-West Germanic*ist—
4Proto-Germanicisti—
5Proto-Indo-Europeanh₁ēs-to be
Every word from Proto-Indo-European h₁ēs- →Every word from Proto-Germanic isti →Every word from Proto-West Germanic *ist →